The present invention relates to a woven mesh substrate with semiconductor elements and to a method and a device for manufacturing such a substrate, and more particularly relates to a technique that makes it possible to exploit a woven mesh substrate with semiconductor elements in which a plurality of spherical semiconductor elements having a light-receiving function or a light-emitting function are installed on a woven mesh substrate in net form that is made up from a plurality of vertical strands that are insulating and a plurality of horizontal strands that are conductive.
From the past, development has been underway of light reception devices such as solar batteries and so on, and of light emission devices such as EL displays and so on, having a construction in which a thin layer of semiconductor is formed over a flexible sheet that is insulating or conductive. While such semiconductor devices, over the whole range from small to comparatively large, can be manufactured by individually and sequentially forming thin semiconductor layers and electrodes and wiring and so on, they are all planar type semiconductor devices, and are formed upon standard sheets.
On the other hand, light-receiving and light-emitting devices using spherical semiconductor elements have been proposed. For example, in Patent Document #1, there is disclosed a flexible solar cell having a construction in which spherical semiconductor elements (i.e. spherical solar cells), in each of which a p n junction shaped as a spherical surface is formed on a spherical p type silicon crystal, are adhered to two aluminum sheets that are adhered together via an insulation layer, and the p type layers and the n type layers of the semiconductor elements are respectively connected to these aluminum sheets.
And in Patent Document #2 there are disclosed a light-emitting display and a method for manufacturing it, in which a large number of spherical light-emitting elements (i.e. light-emitting diodes) are arranged along X and Y directions as a matrix on the surface of a flexible plastic film, and electrodes of these spherical light-emitting elements are electrically connected to electrodes that are shaped as sheets.
The devices of Patent Documents #1 and #2 have structures in which solar cells or spherical light-emitting elements are provided on a common film and are electrically connected thereto. In other words, the light reception or light-emitting function is only available on one side of the film, since the construction is such that the light-receiving layer or light-emitting layer is formed all together on only one side of the common film, or such that a plurality of light-receiving units or a plurality of light-emitting units that have been manufactured individually are disposed on only one side of the common film.
On the other hand, in Patent Document #3, there is disclosed a construction in which the light-receiving function or the light-emitting function is available on both sides of the device. In concrete terms, a flexible light-receiving or light-emitting device is disclosed in which a plurality of spherical semiconductor elements are electrically connected with conductive members (conducting lines), and are sealed with resin. For this device, a construction is proposed in which the cells in the column direction are connected in parallel in the vertical direction by a pair of conducting lines, and adjacent conducting lines in the row direction are connected in series by direct coupling. However, when tension is applied in the direction of series connection, the spherical semiconductor elements receive this tension directly, so that there is a danger of the spherical semiconductor elements being torn away.
And in Patent Document #4 a flexible solar battery module is disclosed, having a construction in which spherical semiconductor elements in which pn junctions are formed are solidly pressed into a plurality of meshes of a mesh like structural material (glass cloth) that is flat woven using conducting lines made from glass fibers coated with silver as horizontal strands and non conducting lines made from glass fiber as vertical strands, and, along with electrodes being formed by application of heat at high temperature in this state, also electrical connection of the mesh like structural material and the spherical semiconductor elements is simultaneously performed, and thereafter both sides of the mesh like structure are laminated with resin film.
However, with the manufacturing method of Patent Document #4, since the formation of the electrodes and establishment of the electrical connections between the mesh like structural material and the spherical semiconductor elements are performed simultaneously, accordingly there is the problem that testing for checking the functioning of the spherical semiconductor elements is not possible, because the pushing of the spherical semiconductor elements into the meshes of the mesh like structural material is not performed subsequently to formation of their electrodes. For this reason, even if faulty spherical semiconductor elements are mixed in with the others, this fact cannot be detected, and therefore the defect ratio of the solar battery module becomes high.
Furthermore, with the finished solar battery module, since the spherical semiconductor elements project on one of its surfaces, accordingly light from the rear surface of the solar battery module cannot be effectively utilized, and the light reception sensitivity for light that is incident from the rear surface becomes low, which is undesirable. Moreover, since the flexibility of the solar battery module when the module is mechanically bent is not symmetrical between its two sides but is biased towards one side, accordingly the convenience of use becomes bad.
Thus, with the manufacturing method of Patent Document #5, a light-receiving module in sheet form or a light-emitting module in sheet form that is transparent and flexible is manufactured by preparing a fabric that is flat woven as a mesh like construction from horizontal strands made from insulating filaments and vertical strands made from electrically conductive filaments, by inserting a plurality of spherical semiconductor elements that have a light-receiving function or a light-emitting function and that have positive electrodes and negative electrodes into a plurality of the net like meshes of the fabric in such a state that the polarities of their electrodes are lined up, by connecting the elements in parallel in the vertical direction (i.e. in the column direction) via pairs of conducting and connecting them in series in the horizontal direction (i.e. in the row direction by connecting between conducting lines in the row direction that are adjacent with conducting lines for series connection, and by sealing the resulting fabric within transparent resin sheets.
Since this light-receiving module or light-emitting module of Patent Document #5 is a module in which the spherical semiconductor elements are integrally installed in the fabric, accordingly it is a module which has a double sided light reception or double sided light emission characteristic and with which there is no bias towards either surface of the light reception or light emission module, and thus a flexible module is obtained both of whose sides have the same external appearance, and which moreover can be bent in both directions in a symmetrical manner.    Patent Document #1: U.S. Pat. No. 4,691,076    Patent Document #2: U.S. Pat. No. 5,469,020    Patent Document #3: PCT Laid Open Publication WO2004/001858    Patent Document #4: Japanese Laid Open Patent Publication Heisei 9-16243    Patent Document #5: PCT Laid Open Publication WO2005/041312